The present invention relates to a dispensing device for dispensing at least two fluids. More precisely, the present invention relates to a manually operated dispensing device for dispensing two or more fluids which are contained within respective syringes which are received and supported by the dispensing device.
In the present context, the term "fluid" means a liquid or a substance which is pourable and in a liquefied state as distinct from a gaseous state.
Published international patent application, Publication No. WO 88/02259 discloses a technique of preparing tissue repair promoting substances, which substances are later on applied for tissue repair by means of two separate syringes which are to be operated simultaneously. The two separate syringes contain fibrinogen extracted from blood of a person or patient and a suitable enzyme, such as thrombin, respectively. The fibrinogen and thrombin form together, like in nature, fibrin which is an insoluble network of fiber-like material constituting a kind of tissue glue interconnecting a wound to be repaired. The healing glue also has favourable effect on the process of healing the wound. The tissue glue is advantageously used after surgery.
The technique of dispensing two components from a syringe assembly comprising two separate syringes which are to be operated simultaneously, however, is by no means advantageous as the two syringes are more difficult to operate than a single syringe and further as the initial frictional force of the two syringes far exceed the frictional force to be exceeded when using a single syringe for dosing a small amount of material from both syringes. Therefore, the technique of applying materials from two syringes which are operated simultaneously inevitably results in an inaccurate dosing of the materials and also in that excessive materials are dispensed from the syringes as an accurate and small amount dosing is simply impossible. The dispensing of excessive materials from the syringes is for numerous reasons inadequate and not advantageous as materials are wasted, which materials are often highly expensive.
As far as the technique of preparing tissue repair constituents or substances is concerned, reference is made to the above published international patent application.
Manually operated dispensing devices for dispensing materials from two or more syringes are also known within the art. Examples of such dispensing devices are disclosed in U.S. Pat. No. 4,690,306, published European patent application No. 0 363 967, published European patent application No. 0 408 494, published German patent application No. 32 34 250, published German patent application No. 36 02 975, and published German patent application No. 39 03 305. Reference is made to the above-mentioned patents and published patent applications, and the above-mentioned U.S. patent is further incorporated in the present specification by reference.
Common to the prior art dispensing devices for manually dispensing or dosing two or more fluids is the fact that the dispensing devices are not adapted to dispense small amounts of fluids in exactly dosed amounts. A further drawback relates to the initial frictional forces of the dispensing devices which result in that a fairly high initial frictional threshold has to be exceeded for dispensing the fluids which renders it difficult to dispense small amounts of fluids by means of the dispensing devices according to the prior art at small or fairly small operational power or pressure levels, such as pressure or power levels generated manually by e.g. a person of the staff of a hospital, such as a doctor or a nurse.
An object of the present invention is to provide a manually operated dispensing device for dispensing at least two fluids, by means of which dispensing device small amounts of fluids may be accurately dispensed or dosed in exact amounts and at small operational power levels.
A further object of the present invention is to provide a manually operated dispensing device for dispensing at least two fluids which is easily manually operable by a person.
An advantage of the present invention resides in the fact that a manually operated dispensing device is provided comprising a minimum set of components which may be manufactured from low-cost materials rendering it possible to produce a fairly cheap, yet easily operable and exact dosing or dispensing device.
A particular feature of the present invention relates to the fact that the manually operated dispensing device according to the present invention is prevented from unintentionally dispensing fluids prior to the intentional use of the dispensing device which efficiently prevents the unintentional waste of materials or fluids.
The above objects, the above feature, and the above advantage are, together with numerous other objects, features, and advantages which will be evident from the below description, obtained in accordance with the teachings of the present invention by means of a dispensing device for dispensing at least two fluids, comprising:
housing means of a pistol-like configuration defining an inner space for receiving and fixating a first and a second syringe containing a first and a second fluid, respectively, each of said syringes comprising:
a syringe housing of an elongated configuration defining opposite proximal and distal ends, PA1 a piston rod received within said syringe housing and defining together therewith a syringe chamber in which said fluid is confined, said piston rod protruding from said proximal end, and PA1 a dispensing aperture being provided at said distal end, said dispensing aperture communicating with the surroundings relative to said inner space of said housing means,
handle means constituting a component of said housing means and including a manually operable, spring-biased trigger means movable relative to said handle means from an inactive position to an active position,
propeller means received within said inner space of said housing means and movable relative thereto for moving said piston rods of said syringes from said proximal ends towards said distal ends for dispensing said fluids from said syringes,
transmission means switchable between a disengaged and an engaged position for transmitting the motion of said trigger means to said propeller means as said trigger means is moved from said inactive position to said active position for generating a uni-directional motion of said piston rods from said proximal ends towards said distal ends, provided said transmission means are in said engaged position and for preventing the transmission of the motion generated by said trigger means, provided said transmission means are in said disengaged position, and
switch means received by said housing means switchable between a first and a second position, in which first position said transmission means is in said disengaged position, and in which second position said transmission means is in said engaged position.
The dispensing device according to the present invention may be employed for manually dispensing two or more sets of fluids which are to be mixed prior to use, such as adhesives or glues to be composed of two or more constituents, or drugs also to be composed of two or more constituents. The dispensing device according to the present invention is preferably used for dispensing tissue glue, e.g. the tissue glue or tissue repair promoting substances disclosed in the above-mentioned international patent application, Publication No. WO 88/02259.
In accordance with the teachings of the present invention, a dispensing device is provided, comprising propeller means, transmission means, and switch means housed by a housing means of the dispensing device, which housing means also receives and fixates two or more syringes containing the fluids to be dispensed by means of the dispensing device. The propeller means of the dispensing device may be constituted by any appropriate means serving the purpose of propelling the piston rods of the syringes from the proximal ends towards the distal ends of the syringes for dispensing the liquids from the syringes. The propeller means may be propelled in any motion, such as a linear motion, a rotational motion, or any combination thereof. Preferably, the propeller means is adapted to perform a linear displacement or longitudinal motion relative to the housing means of the dispensing device for displacing the piston rods of the syringes.
The transmission means of the dispensing device according to the present invention serves the purpose of transmitting the motion of the trigger means to the propeller means for generating a uni-directional motion of the propeller means, and consequently the piston rods, provided the transmission means are in an engaged position. In the present context, the term "a uni-directional motion" is to be construed as comprising any motion according to which the main motional direction is uni-directional which means that the propeller means, and consequently the pistons of the syringes are moved in a single direction. The term "uni-directional", thus, implies that the motion in question is performed in a single direction from an initial position to an intentional position and implies that a reversal of the direction of motion is prevented. Thus, the transmission means of the dispensing device according to the present invention prevents the motion or displacement of the piston rods of the syringes being reversed.
The switch means of the dispensing device according to the present invention may be constituted by any separate or integral appropriate part, component or means of the dispensing device, such as a separate switch, a separate component fulfilling the purpose of switching the transmission means of the dispensing device from disengaged to engaged position and, if appropriate, vice versa.
According to the presently preferred embodiment of the dispensing device according to the present invention, the switch means is constituted by a cover of the housing means, which cover is shiftable from an open position to a closed position, which open position constitutes the first position, and which closed position constitutes the second position of the switch means. Consequently, as the cover of the housing means constituting the switch means is closed, the transmission means is engaged, allowing the dispensing of the two or more fluids from the syringes of the dispensing device.
The cover may constitute a separate component of the housing means of the dispensing device, or preferably constitute an integral component of the housing means of the dispensing device, which cover in the second position seals the inner space of the housing means fully or partially so as to fully or partially conceal the syringes within the inner space of the housing means. Thus, it may be preferable to leave the distal ends of the syringes free for inspection to give the operator a warning of the approaching emptying of the syringes. The syringes may be of identical structure or different structure and may be of identical or different volumetric capacity, f. inst. of different cross-sectional area. Also, the distance of displacement of the piston rods of the syringes may be identical or different, in which first instance the propeller means of the dispensing device according to the present invention may be constituted by a single propeller means, whereas in the second instance, the propeller means of the dispensing device preferably comprise separate first and second propeller means cooperating with the first and the second syringe, respectively.
Provided the propeller means comprise separate first and second propeller means, the transmission means of the dispensing device also preferably comprises separate first and second transmission means cooperating with the first and the second propeller means, respectively, in order to transmit the motion of the trigger means to the first and second propeller means, respectively.
By providing separate first and second transmission means cooperating with the first and second propeller means, respectively, it is rendered possible to dispense one of the fluids from one of the syringes independent of the dispensing of the fluid from the other syringe. Thus, in some instances, it is advantageous and desirable to add a small amount of one of the fluids to a mixture which is rendered possible by separately activating one of the transmission means independent of the other transmission means for causing the propeller means cooperating with the transmission means in question to generate a uni-directional motion of the piston rod of one of the syringes towards the distal end of the syringe in question, still provided the transmission means is in the engaged position.
The mixture of the two or more fluids is characterized by a ratio of mixture, and more precisely a ratio determined by the amount of one of the fluids as compared to the amount of the other fluid of the mixture. The dispensing device according to the present invention renders it possible to dispense two or more fluids of a constant ratio of mixture of the two or more fluids. Provided the syringes containing the two or more fluids in question are of different structure, the ratio of mixture is determined by the cross-sectional areas of the syringes in question, exclusively, provided a single propeller means is employed. In case separate transmission means and separate propeller means are employed, the ratio of mixture is furthermore determined by the ratio of transmission of the transmission means in question, and consequently of the ratio of displacement of the piston rods of the syringes caused by the activation of the spring-biased trigger means of the dispensing device. Provided separate first and second transmission means cooperating with separate first and second propeller means are provided, the ratio of transmission of one of the transmission means, or both transmission means, may be adjusted for adjusting or altering the ratio or mixture of the two fluids dispensed by the dispensing means by adjusting the transmission means which are constituted by adjustable transmission means.
The transmission means being common or independent transmission means cooperating with a single propeller means or independent propeller means may be constituted by any appropriate transmission means allowing a uni-directional motion of the piston rods from the proximal ends to the distal ends thereof. The transmission means may e.g. be constituted by frictional transmission means or preferably be constituted by ratchet means. Further preferably in accordance with the presently preferred embodiment of the dispensing device according to the present invention, the ratchet means comprise toothed rack means cooperating with the propeller means for generating the uni-directional motion of the propeller means. Alternatively, the ratchet means may comprise toothed wheels or toothed wheels cooperating with toothed ratchets or additionally comprising frictional means or any additional motion transmission or motion directional means.
In accordance with a particular aspect of the present invention, the propeller means comprises a single propeller body provided with recesses for receiving the piston rods of the syringes. The propeller body further preferably is provided with recesses allowing the piston rods of the two syringes to be arranged or received by the propeller body from opposite sides of the propeller body, allowing an extremely adequate and simple technique of mounting the syringes relative to the dispensing device. Thus, the syringes may constitute integral or separate components of the dispensing device and, provided the syringes constitute separate components, the syringes may contain fluids of e.g. highly different cost or highly different toxicity. In case the fluids contained within the two syringes are different, and further provided the two fluids are to be handled in accordance with different routines, taking into due consideration the difference of cost or toxicity of the two fluids, the provision of a propeller body having recesses for receiving and cooperating with the piston rods of the two syringes from separate or opposite sides renders it possible to arrange and mount the syringes within the dispensing device by firstly arranging the syringe containing the less expensive or less toxic fluid within the dispensing device and adjusting the propeller body relative to the syringe in question and secondly arranging the syringe containing the most expensive or most toxic fluid within the dispensing device and adjust the position of the propeller body relative to the housing means by dispensing or wasting the less expensive or less toxic fluid from the dispensing device without wasting any of the more expensive or more toxic fluid.